Brake actuating mechanism



Dec. 9, 1941. R. H. Rosi-:NBERG 2,255,578

BRAKE AGTUATING MECHANISM Filed June 28, 1940 2 sheets-sheet 1 Jn-YM ATTORNEYS.

Dec. 9, 1941. R, H, ROSENBERG 2,265,578

BRAKE ACTUATING MECHANISM 2 sheets-sheet 2 Filed June 28, 1940 Patented Dec. 9, 1941 BRAKE ACTUATING MECHANISM Ralph H. Rosenberg, Detroit, Mich., assigner to Detroit Duo-Grip Brake Company, Detroit, Mich., a corporation of Michigan Application June 28, 1940, Serial No. 342,987

(Cl. 18S- 76) Z'Claims.

This 4invention relates broadly to brakes for motor vehicles and more speciiically to improvements in mechanism for neutralizing the torque reactions therein.

In my prior Patents No. 2,143,998, issued J anuary 17, 1939 and No. 2,192,696, issued March 5, 1940, I have disclosed a vehicular brake which embodies generally an internal and external brake shoe organized for simultaneous application through a fork mounted to straddle the ange of the brake drum and oscillate about an axis parallel thereto.

My present invention comprehends a brake assembly which constitutes an improvement of the forms previously disclosed through the provision ofA a combination of levers arranged to permit the prerequisite independent movement of certain parts of the assembly in relation to others and the provision ofvlinkage which will multiply the eort of application upon the braking surface of the drum. i

More particularly my invention is designed with the object of utilizing the principles previously set forth in the brake actuating mechanism with a hydraulic actuating unit and to arrange the connections with the brake shoes in such a manner as to relieve the unit from the torque effect normally imposed thereon.

Other objects and advantages reside in the specific construction and aggroupment of elements peculiar to my structure as will become apparent from the following description and accompanying drawings, which disclosure, it is b elieved, will sufce to impart a clear understanding of the invention as identiiied by the claims appended hereto.

In the drawings:

Fig. 1 is a transverse sectional view through the rear axle of a motor vehicle illustrating in elevation the brake shoes andv operating mechanism therefor;

Fig. 2 is a vertical section through the brake mechanism illustrated in Fig. l, the section being taken on a plane indicated by line 2-2 of Fig. i;

Fig. 3 is a transverse sectional view of the brake mechanism illustrated in Fig. l, the section being taken on a plane indicated by the line 3-3 of Fig. 2;

Fig. 4 is an elevational view of a modified form of the invention;

Fig. 5 is a rear elevational view of the brake shoes and actuating mechanism shown in Fig. 4, a portion of the brake drum being broken away and shown in section;

structure for one end of the external brake shoe, the section being taken on a plane indicated Vby line 8-6 in Fig. 4; and

7 is a transverse sectional view of an end portion of the external brake shoe and the supporting arm therefor, the section being taken lon a plane indicated by line I-I of Fig. 6.

Referring to the drawings, the improved brake structure is shown as coordinated with a vehicular axle comprising, a drive shaft I0 extending through a housing I I and having keyed to an end thereof a hub I2 for the support of a brake drum I3 and wheel I4 of 4the conventional form. Formed on the axle housing II there is an annular flange I5 having an arm I6 mounted thereon which is constructed with a boss Il in the free end thereof. The arm I6 adjacent the boss I1 is formed 'with a lug which is split and cross drilled to receive a bolt I8 to facilitate the adjustable securement of a pin I9.

The externalbrake shoe 2 I, as provided herein,

is fulcrumed on the pin I9 and connected with the internal brake shoe 22 by means of links or forks 23 and 2l. As shown in Figs. 1 and 2, the forks are preferably constructed with arms 25 having pintles 26 and 2l pressed therein or may be formed as integral structures. The pintles 2S lare pivotally connected to the external shoe 2|, the internal brake shoe 22 being pivotally mounted on the pintles 2l which are provided with eccentric head portions 28 to facilitate the adjustment of the brake shoes toward and away from each other. Formed in an end of the forks 23 and 24' there are split bosses 3| which are adapted to have the eccentric head portions of the pintles adjustablyv clamped therein by the bolts and nuts 32.

Secured to the axle housing I0 there is a suitable uid actuating mechanism such as a cylinder 35 having a reciprocating piston therein with a piston rod 36 projecting therefrom. Pivotally mounted on the end of the piston rod there is a `lever 31 having the opposed end thereof keyedl to a shaft 39. Ailixed to the shaft 39 there is an Fis. 6 is a sectional view of the supporting 55 is a lip or ange 45 which is drilled and tapped brake mechanism connected to the cylinder 35.

Upon the movement of the lever 31 the shaft 39 and arm 40 will be oscillated, thereby actuating the rod 4| and thus moving the external and internal brake shoes into engagement with the brake drum I3. The movement of the internal shoe 22 towards the brake drum will cause the forks 23 and 24 to fulcrum about the pintles 26 in the external shoe, thereby urging the external shoe towards the brake drum contemporaneous the movement of the internal shoe towards said drum. Since one end of the external brake shoe 2| is fulcrumed on the pin I9 the actuation of the rod 4I will cause the forks to twist about the pintles mounted therein, which movement results in the brake shoes being moved circumferentially about and towards the brake drum I3 with an equal and uniform pressure.

In brake structures of the type in which the fluid actuating unit embodies a single piston rod for actuating the brake shoes, the actuating mechanisms frequently fail under the excessive torque reaction imposed thereon. The brake structure disclosed in the'present invention is provided withra plurality of arms and levers interposed between the fluid actuating unit and the brake shoes which are adaptedto mitigate the reactionary torque eect heretofore imposed on the unit. More particularly, the utilization of a. connection composed of a plurality of cranks between 'che fluid actuating unit and the brake shoes relieves the unit from the deleterious effects resulting from me torque reaction of the brake shoes and drum.

In the modification shown in Figs. 4 through 6,

the external and internal brake shoes 50 and 5|,

respectively, are pivotally mounted on pintles secured in the forks 53 and 54 in a manner similar to that described for the links shown in Fig. 1.

However, the external brake shoe 50 is afilxedvto thearm 55 in a somewhat different manner. Secured to the arm 55 there is a block 56, Figs. 6 and 7, having a reduced end portion 51 which is adapted to be inserted in an opening 58 formed inthe external brake shoe 50. Formed on opposed sides of the reduced end portion 51 there are' ribs 5,9 adapted in conjunction with the lrounded portions formed on the remaining sides to afford a slight pivotal or fioating movement of the shoe relative to the block. Screw threaded in the brakev shoe there is a pin which is adapted to engage a groove formed in the reduced end clamped to a shaft 69. The shaft 69 `is supported in brackets on the housing and has keyed upon an end portion thereof a crank arm 10 which is formed with a cylindrical socket for the reception of the rounded end portion of a link 1 I.

`The opposed end of the link is likewise rounded for engagement within a cylindrical socket on the end of the internal brake shoe 5|. y

The operation of the modified brake structure is thesame as that described for the brake shown in Figs. 1 through 3, in that the movement of the piston rod 61 and lever 68 as indicated by the arrows (Fig. 4) will cause the oscillation of the shaft 69 and arm 16, 'the actuation of the link 1| and forks 53 and 54 and consequent actuation of the internal and external shoes. By virtue of the adjustability of the supporting rod 63'and the floating movement afforded through the block 56 the external brake shoe may be driven into full concentric engagement Withfthe drum during the operation thereof Without undue Wear upon any localized portion thereof.

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it isv to be understood that the specific terminology is not intended to be restrictive vor confining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. A brake mechanism comprising, a brake drum, an internal and external brake shoe engageable therewith, a fixed `arm having one end of the external brake shoe mounted thereon, pendulant links intermediate said inner and outer shoes and aiiixed thereto, a cylinder having a fluid actuated piston therein, a stop on said arm to delimit the inward movement of one end of said internal brake shoe, an abutment on the opposite end of the internal brake shoe, a rod pivotally connected thereto, a lever ailixed to said piston and disposed in parallel relation to said rod, and an arm connected to said lever and rod for actuating said rod to effect the oscillation of said links.

2. A brake mechanism comprising, a brake drum, an-internal and external brake shoe engageable therewith, a fixed arm having one end of the external brake shoe mounted thereon, a pair of forks uniting the brake shoes, a cylinder having a fluid actuated piston therein, a piston rod extending from said cylinder, a lever pivotally mounted thereon, a shaft having said lever keyed thereto, an arm affixed on said shaft, a, rod interposed between said arm and one of the brake shoes for oscillating the forks and means secured to one of said shoes to delimitv the radial move-- ment thereof.

RALPH H. ROSENBERG. 

